Abstract

The Wedge-tailed Shearwater, Puffinus pacificus, colony on Heron Island, Great Barrier Reef, Australia, has been the subject of a long-term
study since 1984 to monitor the effects of development. During this time, there has been considerable development in the tourist resort,
university research station and national park ranger quarters. Several methods have been used to record and analyse the effects of development.
Prior to the development of specialised burrow-viewing equipment, Wedge-tailed Shearwater population estimates had been based
on indirect methods such as footprints and cleared burrow entrances. Investigation of actual burrow contents, relayed electronically from
a camera inserted into burrows showed that all previous population estimates needed revision, even halving earlier populations estimates.
We also used a photographic record and surveys to record the changes to island habitats over time. The Ultimate Environmental Threshold
(UET) technique was used to estimate the effects of development on several environmental factors. Traditional breeding areas have been
lost to the shearwater population through construction of buildings, paving of areas, blocking of flight paths and compaction of tracks.
However, the species appears to have compensated despite significant modification to the island's natural habitats. Nesting behaviour has
been altered in disturbed areas of the island and egg-hatching rates have been lowered. Because the life span of a shearwater could be up
to 30 years, more long-term research is needed to analyse the true effects of development.